package com.discuss.community.service.impl;

import com.discuss.community.service.LikeService;
import com.discuss.community.util.RedisKeyUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.dao.DataAccessException;
import org.springframework.data.redis.core.RedisOperations;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.SessionCallback;
import org.springframework.stereotype.Service;


@Service
public class LikeServiceImpl implements LikeService {

    @Autowired
    private RedisTemplate<String, Object> redisTemplate;

    @Override
    // 点赞
    public void like(int userId, int entityType, int entityId, int entityUserId) {

        redisTemplate.execute(new SessionCallback<Object>() {
            @Override
            public Object execute(RedisOperations operations) throws DataAccessException {
                String entityLikeKey = RedisKeyUtil.getEntityLikeKey(entityType, entityId);
                String userLikeKey = RedisKeyUtil.getUserLikeKey(entityUserId);

                Boolean isMember = operations.opsForSet().isMember(entityLikeKey, userId);

                operations.multi();

                if(isMember) {
                    operations.opsForSet().remove(entityLikeKey, userId);
                    operations.opsForValue().decrement(userLikeKey);
                }else {
                    operations.opsForSet().add(entityLikeKey, userId);
                    operations.opsForValue().increment(userLikeKey);
                }

                return operations.exec();
            }
        });

    }

    // 查询某个实体的点赞数量
    @Override
    public long findEntityLikeCount(int entityType, int entityId) {
        String entityLikeKey = RedisKeyUtil.getEntityLikeKey(entityType, entityId);
        return redisTemplate.opsForSet().size(entityLikeKey);
    }

    @Override
    public int findEntityLikeStatus(int userId, int entityType, int entityId) {
        String entityLikeKey = RedisKeyUtil.getEntityLikeKey(entityType, entityId);
        return redisTemplate.opsForSet().isMember(entityLikeKey, userId) ? 1 : 0;
    }

    @Override
    public int findUserLikeCount(int userId) {
        String userLikeKey = RedisKeyUtil.getUserLikeKey(userId);
        Integer count = (Integer)redisTemplate.opsForValue().get(userLikeKey);

        return count == null ? 0 : count;
    }


}
